1. Field of the Invention
The present invention relates to power amplifiers, and more particularly, to a power amplifier that can increase power efficiency by preventing power consumption caused by DC components from an RF input signal.
2. Description of the Related Art
Mobile communications terminals have been widely used because they are easy to use. As the use of these mobile communications terminals has increased, it has become important to run various kinds of applications to meet consumer demand and allow for long-time use at the same time.
In order to extend the use time of a mobile communications terminal, it is important to increase battery capacity. However, the size of batteries is limited since small, lightweight, and thin mobile communications terminals are in demand in the market. Therefore, there is a need to increase the power efficiency of main elements inside a mobile communications terminal.
In order to transmit and receive RF signals, this mobile communications terminal uses a power amplifier. This power amplifier takes up a considerable portion of the overall power consumption of the mobile communication terminal.
Thus, the power efficiency of the power amplifier needs to be increased. However, as for a power amplifier being used in a mobile communications terminal according to the related art, DC current flows through the power amplifier at all times, which reduces power efficiency.